Brake apparatus.



No. 726.864. PATENTED MAY 5, 1903.

P. L. CLARK. BRAKE APPARATUS.

APPLICATION FILED AUG. 8. 1900.

N0 MODEL. 3 SEBETF-BHEBT 1.,-

N 'Q N WITNESSES: INVENTOR,

No. 726,864. A PATENTBD MAY 5, 1 90's.

- I. L. CLARK.

. BRAKE APPARATUS.

APPLIOAIION'IILBD AUG. 8. 1900. no MODEL. s snare-sum. 2.

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. llllllqlh PATENTED MAYY5, 1903.

I. L. CLARK. BRAKE APPARATUS.

APPLICATION FILED AUG. B, 1900.

N0 MODEL.

Patented May 5, 1903.

"ATENT FFICE.

FRANCIS L. CLARK, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE AIR BRAKE OOMPANY OF PI TTSBURG, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA.

BRAKE APPARATUS.

SPECIFICATION forming part of Letters Patent No. 726,864, dated May 5, 1903.

Application filed August 8 1900. Serial No. 26,244. (No model.)

T at whom it may concern:

Beit known that I, FRANCIS L. OLARK,a citizen of the United States,resid in g at Pittsburg, county of Allegheny, State of Pennsylvania, have invented or discovered a certain new and useful Improvement in BrakeApparatus, of whichimprovement the followingis aspecification.

My invention relates to railway brake apparatus, and has for its object to provide an improved and compact arrangement of floating levers adapted to be connected to the rods of the brake-rigging of cars or locomotives.

My invention consists in an improved construction of floating levers in which one lever is carried by another lever; and it also consists in an improved construction in which the levers are mounted upon the same axis or pivot and in certain other combinations and arrangements of parts hereinafter described and claimed.

In the drawings, Figure 1 is a vertical longitudinal section of a six-wheeled truck, showing my improved brake apparatus applied thereto. Fig. 2 is a transverse section taken on the line a; a; of Fig. 1. Fig. 3- isan enlarged detail view of 'the'doublefloating levers, showing the manner in which they are mounted on their common axis or pivot. Fig. 4 is a section taken on the'line y 'y of.Fig. 3. Fig. 5 is a view showing my improved brake apparatus applied to the driving-wheels of a locomotive. Fig. 6 is an end view of the construction shown in Fig. 5, and Fig. 7 a plan view thereof.

In Figs. 1 and 2 of the drawings I have shown an ordinary six-wheeled car-truck having frame 7, three pairs of wheels 1, 2, and 3, with their axles4, 5', and 6, brake-beams 8, 9, and 10, and brake-shoes 11, 12, and 13, respectively.

The floating lever -14is pivoted upon the pin or axis 27, which issuspended, by. means of hangers or links 17, from'the' spring 16, which is secured to some stationary part of the truck-frame. The upper end of the lever 14 is pivotally connected at 18to the pull-rod 19, and the lower end is coupled at 20 to the rod 21', which is connected to the brake-beam 10. The lever 15 is also pivoted on the same axisor pin 27 as is lever 14, and its upper end is pivotally connected with rod 25 of the brake-beamB, while its lower end is pivotally connected with the rod 26 of the brake-beam 9. The specific construction of the floating levers and their connections is more clearly shown in Figs. 3 and 4. The lever 14 is made up of the two parts or bars 14 and 14", spaced apart and secured together at their ends by means of pins or bolts 18 and 20. The pin or bolt 27, which forms the axis of the le vers,-is provided with two spacing-collars 28 on the outside of the bars 14 and 14 and with another spacingcollar 29 between the parts or bars 14 and 14 of the floating lever 14. Thehangers 17 have a bearing-surface on the collars 28, and the lever 15 is mounted. to turn upon the collar 29 between the two bars 14 and 14 of lever 14. The bearing-surface of the collars 28 is slightly wider thangthe thickness of the hangers 17, and thebearing-surface of the collar '29 is wider than'the hub30 of the lever 15, so that when the nut 31 of the bolt 27 is screwed up the collars 28 and 29 and the two bars 14 and 14 of the floating lever 14 will be tightly clamped together, and the bearing-surface of the floating lever in the hangers will be on the collars 28 and the bearing-surface of the lever 15 will be on the collar 29. A washer 32 may be provided at each end of the bolt 27. The ends of the bars 14 and 14 are secured together-by bolts 18-and 20, and the bars are spaced apart at their ends by means of the collars 33 and 34, which are mounted on the bolts between the bars. The pull-rod 19 and connecting-rod 21 are pivotally connected to the collars 33 and 34, respectively. The

rods 25 and 26 extend through a safety-loop 24, which is suspended from the truck-frame, so that the rods will be prevented from falling to the ground in case they should become disconnected or broken inany way.

The brakes may be applied by hand or by fluid-pressure in the usual way the devices for actuating the brake mechanism being connected to the-pull-rod,19.,.. Whemthe devices are operated to apply the brakes, the

pull-rod 19 is drawn to the right, turning the lever 14 about its axis or pivot 27, pulling the rod 21 toward the left until brake-shoes ICO 13 bear upon the wheels 3. The lever 14 will then turn about the point 20 as a fulcrum, carrying the pivot 27, together with lever 15, to the right until the brake-shoes 11 bear against the wheels 1. Then as pivot 27 continues to move to the right the lever 15 will turn on its pivot 27 and also about the point 22 as a fulcrum until the brakeshoes 12 bear against the wheels 2. The spring 16 constitutes a yielding elastic means for suspending the lever and allows an automatic vertical adjustment of the position of the lever to accommodate the direction of the resnltant strains on opposite sides ofthe lever when the brakes are applied, and this is an important feature, for it often happens that owing to the wear of the brake-shoes and various other causes the resultant forces will not be exactly balanced and there will be a tendency to draw the lever down. The spring then yields and allows the lever to move down until the forces are equalized on opposite sides of the lever. The length of the arms of the lever 1i on opposite sides of the pivot being equal to each other and the length of the arms of the lever 15 being also equal to each other, it is clear that the force exerted by rod 21 to apply the brake-shoes 13 is equal to the force applied by the pull-rod 19, and the force tending to move the pivot 27 to the right is double the amount of force exerted by the pull-rod 19, since the length of the power-arm is double that of the resistancearm. This double force is applied at the center of lever 15, tending to turn it about either of its ends as a fulcrum, and thus exerting a pull in each of the rods 25 and 26 equal to one-half of the force applied at the pivot 27- that is to say, equal to that applied by the pull-rod 19. By this arrangement the brakeshoes are all applied with equal pressure to the wheels. It is not necessary, however, that the length of the lever-arms on opposite sides of their pivots should be equal nor that the brake-shoes should be applied with equal pressure to all the wheels, for in case some of the wheels carry more weight than others the brake-shoes may be applied with greater pressure to the wheels carrying the heavy load than to those carrying a lighter load by merely varying the relative lengths of the lever-arms to give the desired pressure to the respective brake-shoes.

In Figs. 5, 6, and 7 I have shown my in vention applied as a driver-brake to a locomotive having three pairs of driving-wheels 11, 12, and 43, carrying the frame 44:, to which are hung the brake-beams 45, 16, and -17. The brake-cylinder 48 is shown mounted on the frame and has its piston-rod connected with the upper end of the floating lever 14, which in this case is bifurcated at its lower end and pivoted on the brake-beam 4:5. The lever 15 is pivoted at 27 in the bifurcated end of lever 1a and hasits arms of unequal lengths,

the longer arm being connected by rod 49 with the end of lever 50, which is pivoted to the brake-beam 46 and also to the frame at the point 51, and the shorter arm of lever 15 being connected by rod 52 with the brakebeam 47. The relative lengths of the leverarms are so proportioned as to give the desired pressure of the brake-shoes on the wheels. By this arrangement the pivot 51, at which the system of levers is connected to the engine-frame, is not subjected to a great strain, as it is in the case of other systems, where the cylinder-lever is pivoted directly to the frame and transmits the entire braking force to all the wheels. This excessive strain on the pivot connected to the engineframe has been found to be an objectionable feature, and this is entirely avoided by the use of my improved construction as shown in Fig. 5, in which the brake-lever system is pivoted to the engine-frame only at the point 51, and there will be very little strain at this point.

l/Vhile I have shown but two constructions of brake apparatus adapted for use in connection with my compound floating lever, it is to be understood that my invention is not limited to these particular constructions, but covers, broadly, any arrangement of brakerigging in which a compound floating lever having a yielding elastic support is used.

Having now described my improvement in brake apparatus, what I claim as new, and desire to secure by Letters Patent, is-

1. A compound floating lever, comprising one lever having a yielding elastic support and another lever mounted on the first lever.

2. A compound floating lever, comprising one lever pivoted to a yielding elastic support and another lever pivoted on the axis of the first lever.

3. In a brake apparatus, a floating lever, having a yielding elastic support, another lever mounted on the first lever and connections for applying the brakes by the movement of the levers.

4:. In a brake apparatus, the combination, of a springsupported floating lever con nected to a pull-rod and one of the brake-beams, and another lever carried by the first lever and connected to the other brake-beams.

5. In a brake apparatus, the combination, of a lever flexibly suspended at its pivot or axis, another lever carried by the first lever, and connections from the levers to the brakeactuating mechanism and to the brake-beams.

6. In a brake apparatus, the combination, of an elastically-suspended floating lever, another lever carried by the first lever, and connections, from the levers to the brake-actuating mechanism and to the brake-beams.

7. Ina brake apparatus, the combination of a floating lever, elastic means for suspending said lever, another lever carried on the same pivot or axis with the first lever, and connections, from the levers to the brakebeams and to the brake-actuating mechanism.

8. In a brake apparatus, the combination,

of a floating lever flexibly hung at its pivot or axis, another lever carried on the same pivot with the floating lever and connections from the levers'to the brake-actuating mechanism and to the brake-beams.

9. In a brake apparatus, a floating lever comprising two bars spaced apart transversely and another lever pivoted between said bars.

10. In a brake apparatus, a floating lever composed of two parallel bars secured together and spaced apart, two hangers pivoted on the axis of the lever outside the bars and another lever pivoted on the axis of the floating lever between said bars.

11. Ina brake apparatus, a floating lever, two hangers pivoted on the axis of the said lever, collars located on the axis for bearings in the hangers, and another lever pivoted on the same axis.

rying spacing-collars'between and outside of said bars, hangers pivoted on the outside collars and another lever pivoted on the collar between the bars;

In testimony whereof I have hereunto set my hand.

FRANCIS -L. CLARK; Witnesses:

R. F. EMERY,

J AS. L. MAODONALD; 

